Weft thread inserting device for shuttleless looms

ABSTRACT

This invention relates to an improvement in a weft thread inserting device for shuttleless looms comprising gripper rods which move in a reciprocating fashion and laterally engage into the shed, and wherein gripper heads positioned at the forward end of the gripper rods are equipped with clamping means for the weft thread comprising a movable clamping part and a stationary counter bearing, the improvement comprising a soft elastic base means mounted at the counter bearing, and a wear resistant top means floatingly positioned thereon.

United States Patent [191 Kokkinis Dec. 3, 1974 WEFT THREAD INSERTING DEVICE FOR SHUTTLELESS LOOMS [75] inventor: Nikolaus Kokkinis, Eriskirch,

Germany [73] Assignee: Lindauer Dornier Gesellschaft mbH., Lindau/Bodensee, Germany [22] Filed: May 15, 1973 [21] Appl. No.3 360,430

[30] Foreign Application Priority Data Aug. 14, 1972 Germany 2240009 [52] US. Cl 139/122 N [51] Int. Cl D0311 47/20 [58] Field of Search 139/1, 122 R, 122 N, 194, 139/125, 126

[56] References Cited UNITED STATES PATENTS Llado 139/122 l/1972 Pfarrwaller 139/122 H 5/1972 Kokkinis 139/122 Primary Examiner-Henry S. Jaudon Attorney, Agent, or FirmJames E. Bryan 5 7 ABSTRACT This invention relates to an improvement in a weft thread inserting device for shuttleless looms comprising gripper rods which move in a reciprocating fashion and laterally engage into the shed, and wherein grip-i per heads positioned at the forward end of the gripper rods are equipped with clamping means for the weft thread comprising a movable clamping part and a stationary counter bearing, the improvement comprising a soft elastic base means mounted at the counter bearing, and a wear resistant top means floatingly positioned thereon.

2 Claims, 5 Drawing Figures The present invention relates to a weft thread inserting device for shuttleless looms comprising a pair of gripper rods which move in a reciprocating fashion and laterally engage into the shed, the gripper heads being provided with clamping means for the weft thread.

In a weft thread inserting device of this type, the weft thread is received on one side outside of the loom by the gripper head of one of the gripper rods, drawn into the shed, and transferred approximately in the center of the shed to the gripper head of the other gripper rod. During the return movement of the gripper rods, the weft thread is thereafter completely pulled through the shed, and finally released once more on the other side of the machine.

In the known looms with thread transfer, approximately in the center of the shed, clamping means are provided for purposes of gripping and releasing the tuatable from the outside by means of control levers coupled to the main drive gear of the loom. The clamping means consists of a two-armed clamping lever and a plate being disposed laterally at the gripper head as a counter bearing ,for one of the arms of the clamping lever provided as a clamping part. The aforementioned control levers will come to be positioned upon the other arm of the clamping lever. For this purpose, the control levers engage from the outside through the warp threads of the shed. The clamping lever is moved, during its actuation, parallel to the wall of the gripper head. The clamping part itself is shaped prismatically and therefore constitutes a kind of knife edge which, in the position of rest thereof, is placed against a counter piece in the form of a prismatic bed. This prismatic bed is disposed in a lateral plate at the gripper head wall. A good clamping effect is indeed obtained by virtue of this prismatic arrangement and construction, but the thread is bent at this point, which may quite possibly be disadvantageous in the case of delicate weft threads.

Also, it has been previously proposed to arrange an elastic surface under the prismatic knife edge of the clamping part, for example a plastic piece, instead of the prismatic bed. While this solution does afford an improvement, it is not fully satisfactory. Since the weft thread is clamped in firmly by the clamping part at the same spot or point practically at all times, as is indeed required of the clamping device, the plastic overlay or surface is damaged relatively soon at the point being stressed. Grooves will be formed therein and, as a resuit, the clamping effect becomes poorer, and an exact gripping and release of the weft thread is no longer assured. It is necessary therefore to exchange the elastic plastic overlay or surface after only a relatively short period of time, and for this purpose to remove the entire lateral plate at the gripper head.

V weft thread, and these clamping means are forcibly accounter bearing is a soft-elastic base or bed with a wear resistant top or upper part that is floatingly positioned thereon. The counter bearing is preferably provided as a plate which is equipped with two lateral spacer means and is disposed laterally at the gripper head. One of the spacer means of this plate extends in a rectilinear fashion at least at the 'part thereof facing the movable clamping part, and is enclosed with a ring-shaped softelastic base. The top or upper part is shaped in the manner of a clamp or clasp and is inserted between the two' spacer means in a manner such as to be secured against falling out. Effectively obtained in this manner is not only a wear resistant surface on the one hand, and a high degree of elasticity of the base on the other hand, but due to the fact that the top part is floatingly provided on the soft base it is adapted to readily conform to the clamping part in any position. Accordingly, the clamping part and the top part will in any case be positioned flush upon each other, and flawlessly'clamp in the weft thread between each other.

One embodiment of the present invention will now be described in further detail hereinbelow on the basis of and with reference to the accompanying drawing, wherein FIG. 1 illustrates a gripper head with a closed clamping device;

FIG. 2a illustrates the plate serving as counter bearing in a side view thereof;

FIG. 2b illustrates the plate serving as counter hearing in a top plan view thereof;

FIG. 20 illustrates the plate serving as counter bearing in a cross-sectional view thereof, and

FIG. 3 illustrates the top part.

Apparent from FIG. 1 is the disposition or provision of the clamping device at the gripper head. The gripper head inself has been identified with reference numeral 1. Pivotally positioned thereon is a two-armed clamping lever 2. The pivot axis has been identified with reference numeral 3. The two-armed clamping lever 2 is provided at the forward end thereof as a clamping part 2a for the weft thread. At the portion 2b of the clamping lever pointing rearwardly, there engage the control levers (not shown) for opening the clamping device. A leaf-type or flat spring 4 under the arm 2b of the control lever brings about the closing of the clamping device. Disposed at the tip of the gripper head 1 in such a manner as to be laterally removable is a plate 5. Apparent from this figure are also two fastening holes for the plate 5.

The construction or design of the plate 5 is illustrated in further detail in the various views of FlGS. 2a to 20.

' The plate 5 is equipped with two spacer means 5 and It is the object of the present invention to afford a simplification in this respect and, by using the advantages of an elastic counter-piece for the clamping part, to provide a solution which does not have the disadvantages and drawbacks referred to hereinabove, and which clamping part is, in other words, resistant to 'wear and tear so that the frequency change thereof is no longer necessary.

This object is obtained, in accordance with the present invention, by virtue of the fact that disposed at the 5''. Separate structural parts may be provided for the spacer means, but they also may be made integral with the plate. Theh plate 5 has holes 7 and 8 in order that it can be secured to the gripper head 1. The plate 5 has a projection 6 pointing upwardly and forming, with the lateral wall of the gripper head 1, a gap into which one arm of the clamping lever engages, namely the clamping part ZaJThis gap has been shown in FIG. 2c. The clamping part 2a has been omitted from this figure for purposes of greater clarity of illustration. The spacer means 5' is so provided that it extends in a rectilinear manner at the portion thereof facing the clamping part 2a. A ringshaped soft-elastic base 9 is placed around the spacer means 5'. Placed in a floating manner upon this base 9 in the gap between the wall'of the gripper head 1 and the projection 6 of the plate 5 is a top part 1th of a wear resistant material. The most diversified materials may be used for the top part 10, which may consist for example of the material known under the name of Widia, or also of a ceramic material. A nose 1th of the support part engages in the interstice between the two spacer means 5' and 5" so that the top part engages the spacer means 5' approximatelyv in a clamp-like or clasp-like fashion and is secured against falling out because of the elasticity thereof. Since the top part 10 is positioned in the gap between the wall of the gripper head and the projection 6 of the plate 5, it also laterally secured against falling out.

In FIG. 3, the top part 10 has been illustrated separately. As is apparent from this figure, it extends in a straight-lined fashion on the upper side thereof so that the clamping part 2 is adapted to be positioned, or rest, flush thereon. By virtue of the construction of the top part as shown, it is possible during the manufacture to insert the part in a very simple manner in its place where it is held by reason of its shape and because of the elasticity of the soft-elastic base. If needed, however, an exchange, or a removal of the top part is readily possible.

it will be obvious to those skilled in the art that many modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications.

What is claimed is: 1. In a weft thread inserting device for shuttleless looms comprising gripper rods which move in a reciprocating fashion and laterally engage into the shed, and wherein gripper heads positioned at the forward end of the gripper rods are equipped with clamping means for the weft thread comprising a movable clamping part and a stationary counter bearing,

the improvement comprising a soft elastic base means mounted at. the counter bearing, and rigid, wear resistant top means floatingly positioned thereon. 2. A weft thread inserting device according to claim 1 in which the counter bearing plate mounted laterally at the gripper head and equipped with lateral spacer means, one of the spacer means of said plate extending in a straight-line fashion at least at the portion thereof facing the movable clamping part, and a ring-shaped soft-elastic base surrounding said spacer means, said top means being constructed in a clamp-like manner and inserted between said spacer means so as to be secure against falling out.

. UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No; 3,851,676 Dated December 3, 1974 Inventor(s) Nikolaus Kokkinis It is certified that error appears in the above-identified patent and that said Letters Patentare hereby corrected as shown below:

Column 1, line 64; frequency" should read frequent Column 2, line 56, "theh" should read the Column 4, line 17, after "bearing", is a should be inserted.

' Signed and sealed this 4th day of February 1975;

. (SEAL) AttBSt McCOY M. GIBSON JR. 0. MARSHALL DANN Attesting Officer Commissioner of Patents USCOMM-DC 60376-P69 w us. covlnunzlrr PRINTING OFFICE I! o-su-su.

FORM PO-105O (1069) 

1. In a weft thread inserting device for shuttleless looms comprising gripper rods which move in a reciprocating fashion and laterally engage into the shed, and wherein gripper heads positioned at the forward end of the gripper rods are equipped with clamping means for the weft thread comprising a movable clamping part and a stationary counter bearing, the improvement comprising a soft elastic base means mounted at the counter bearing, and rigid, wear resistant top means floatingly positioned thereon.
 2. A weft thread inserting device according to claim 1 in which the counter bearing plate mounted laterally at the gripper head and equipped with lateral spacer means, one of the spacer means of said plate extending in a straight-line fashion at least at the portion thereof facing the movable clamping part, and a ring-shaped soft-elastic base surrounding said spacer means, said top means being constructed in a clamp-like manner and inserted between said spacer means so as to be secure against falling out. 